Abstract

Background

Different cell types have distinctive patterns of chromosome positioning in the nucleus.
Although ectopic affinity-tethering of specific loci can be used to relocate chromosomes
to the nuclear periphery, endogenous nuclear envelope proteins that control such a
mechanism in mammalian cells have yet to be widely identified.

Results

To search for such proteins, 23 nuclear envelope transmembrane proteins were screened
for their ability to promote peripheral localization of human chromosomes in HT1080
fibroblasts. Five of these proteins had strong effects on chromosome 5, but individual
proteins affected different subsets of chromosomes. The repositioning effects were
reversible and the proteins with effects all exhibited highly tissue-restricted patterns
of expression. Depletion of two nuclear envelope transmembrane proteins that were
preferentially expressed in liver each reduced the normal peripheral positioning of
chromosome 5 in liver cells.

Conclusions

The discovery of nuclear envelope transmembrane proteins that can modulate chromosome
position and have restricted patterns of expression may enable dissection of the functional
relevance of tissue-specific patterns of radial chromosome positioning.